Apparatus for measuring the axial thrust acting upon a shaft.



P. WAGNER. v APPARATUS FOR MEASURING THE AXIAL THRUST ACTING UPON A SHAFT. APPLICATION IILBDSEPT. 28, 1910,

1 ,063,625. Patented Junie-,3, 19113.

- 2 SHEETS-SHEET 1.

22/ Flg. I 2

Witnesses: I IhVentor: Daul Wa ner:

I P. WAGNER, APPARATUS POR MEASURING THE AXIAL THRUST- ACTING UPON SHAFT.

I APPLIOA'ILION TILED snmzs, 1910. 1,063,625, I Patented June' 3, 1913. I 2' SHEETS-SHEET 2.

I nQentor: F ul Wa nel',

.7It t L Witnesses:

1 one or both plates transmit the strain of pressure or pull exerted on the one portion 4 UNITED STATES PATENT orrrcn.

PAUL WAGNER, OF BERLIN, GERMANY, ASSIGNOR TO GENERAL ELECTRIC COMP ANY, A CORPORATION OF NEW YORK.

APPARATUS FOR MEASURING THE AXIAL THRUS'I. ACTING UPON A SHAFT.

Patented June 3, 1913.

Application filed September 28, 1910. Serial No. 584,187.

To all whom it may concern Be it known that I, PAU WAGNER, a subect of the Emperor of Germany, residing at Berlin, Germany, have invented certain new and useful Improvements in Apparatus In 'the thrust-measuring devices hereto-- fore employed a coupling has been inserted in the shaft which consisted of elastic plates. The extent of the mutual approxima'tion of these elastic plates, caused by the 'axial thrust served as a measure of the extent of the thrust exerted. This arrangement had the disadvantage that the coupling plates were constantly weighted with i the entire axial pressure so long as such pressure existed. By the present invention such constantly great stram is avoided by providing the coupling plates with stops which after a slight bendlng on the partof of the shaft directly to the other. The measurement of the thrust itself is effected (since by reason of the stops the extent of the elastic flexion cannot serve .as a measure of I the thrust exerted on the shaft) by deterthey assume again,

mining the pressure of a fluid which is pumped in between with relatlon to the above-mentioned stops, tion which they held before a thrust was exert-ed. The total thrust is then received by'the fluid and the pressure thereof as indicatedon a gage, gives a direct measure of the extent of the thrust itself.

I In the accompanying drawing, Figure 1 is a longitudinal section of one embodiment of my invention; Fig. 2 is a cross-section of the same on the line 2-2, Fig. 1; Figs. 3 and 4 are respectively longitudinal and'cross sections of another illustrative form of construction; and Fig. 5 is a partial sectional view of a modification of the apparatus of Figs. 3 and 4.

In the shaft 1, upon which is exerted an axial thrust in the direction of the arrow,

is inserted a plate-coupling 2, the somewhat elastic walls of which include between them, in the form shown in Figs. 1 and 2, a hollow the coupling plates until.

their normal posi-,

space '3 which is filled with fluid under pressure by forcing the latter by the pump 8 into a bore 4: in the shaft, which bore is constantl connected with the hollow space 3; the uid passing through openings 5 which open into the circular chamber 6 in a non-rotatable sleeve 7 surrounding the arbor or shaft. Into the pipe 9 connecting the pump 8 with the circular chamber 6 is further introduced a double exit-pipe 1O andv 12, the former of which may be opened by a valve 13, while in the second is constructed a safety valve 11. These exit pipes open into a receptacle 15 from which the working fluid 'is again supplied to the pump 8 driven by the motor 8. The small amount of fluid passing out between the shaft and sleeve 7 at the sides of the latter is returned likewise to the receptacle 15 through the pipes 16. The coupling of the shaft parts 1 "is effected, 1n cotiperation with the plates 2 connected closely together at the edge, by means of a bayonet oint 17 18. The two parts of this oint are so constructed that, failing any thrust of the shaft, some clearance remains between the ends of the shaft-portions 1 in bot-h longitudinal directions. This middle position of the coupling is indicated by the deflection 13* of two calipers 20 rotatable about the pivots 19, which calipers rest as to their lower ends during the measuring operation, upon the coupling plates near the shaft.

In the construction of Figs. 3 and 4, only the outer part 2 of the plates 2 is elastic, while the partconnected to the shaft 1 is madesuificiently thick to permit the fluid .pressure prevailing between the plates during a measurementto be received without bending. By confining the fluid chamber 3 to the space between these rigid plate portions, the elastic plate portions are freed from any fluid, pressure. The suitable restriction of the chamber 3 is attained by means of a flexible circular membrane 21 located at a suitable height between the coupling plates. In order, however, notwithstanding the non-removable connection of the parts of the coupling by the circular membrane 21, to permit separating from each other in an emergency, the rigid portion of one coupling plate 2 is divided perpendicularly to the shaft axis in such manner that notwithstanding the firm connection of the one part representing one tween the parts of the bayonet joint.

Y ing axial thrust is coupling plates,

. therefor.

ime plate 2' with the one'end of the membrane, the remaining plate portion 52 may be removedat the same time with the shaft belonging thereto after loosening the peripheral screws.

The method of operation is as follows: The thrust of the propeller is, so long as no measurement is taking place, transmitted from one shaft portion 1 to the other not only in forward but also in backward revolution directly through the projections on the bayonet joint 17, 18 or arranged pressure surfaces; the coupling plates 2 bending only to an unimportant degree to correspond to the small play be- For the purpose of measuring the thrust in the direction of the arrow, Fig. 1, a fluid is forced by the pump 8 into the chamber 3 between the plates 2, the pressure radually increasing, and this pumping of uid continues until the free ends of the calipers 20 resting on the coupling plates show by their distance from each other to the extent of 18 th'at'the ends of the shaft have the same distance from each other as before the occurrence of the thrust to be measured, that is, that the total thrust is taken up by the fluid pressure.

In the construction of Figs. 3 and-4, the elastic parts of the coupling plates are in the position shown free from bending strains. The gradual increase in pressure of the fluid forced by the pump is attained by suitable closure of the valve 13, whereby the over-flow to the receptacle 15 is more and more throttled. By suitable adjustment of the gage 22 it is possible to read directly thereon the thrust exerted. By the method given, any desired thrust occurring in other ways, exerted in one direction upon an arbor or shaft, may be determined.

The invention contemplates the use not only of the fluid, but also of a gaseous pressure medium, for example compressed air, the apparatus being suitably constructed Likewise it is not necessary that the entire axial thrust be taken by the pressure medium, but within the limits established by the stops on the coupling, a portion of the thrust may be determined in the former manner by the mutual approximation of the plates, so that the only remaintaken up by the pressure of the medium introduced into the cou pling. Instead of the membrane,

Fig. 3, employed for dividing the hollow chamber between the any other axially adjustable packing may be employed, such for example as the packing 23, Fig. 5, whereby, with suitable construction, the division of the one coupling late for the purpose of the ready release 0 I the coupling parts from each other may be discontinued as unnecessary.

In accordance with the provisions of the through specially patent statutes, I have described the principle of operation of my invent on, together withthe apparatus which I now conslder to represent the best embodiment thereof; but I desire to have it understood that the apparatus shown is only illustrative, and that the invention can be carried out by other means.

What I claim as new and desire to secure by Letters Patent of the United States, is,

1. The combination with a shaft made In sections, of a coupling for said sections comjacentends of the sections and forming a chamber between them that is closed at its periphery, one member and section being movable relatively to the other so as to vary the size of the chamber, means supplying fluid under pressure to the inner portion of the chamber, a pressure indicating device and devices for transmitting rotary motion from One member to the other.

2. The combination with a shaft made in two sections, of'an elastic coupling therefor capable of longitudinal movement, and stops to limit suchmovement and enable thethrust to be directly transmitted when it exceeds a predetermined amount.

3. The combination with a shaft made in two sections,of an elastic coupling therefor capable of longitudinal movement, and a bayonet jointiconnecting together the couthe shaft, said joint permitting axial play.

two sections, of a ho low elastic coupling therefor, a bayonet joint for connecting said sections and limiting and stationary levers bearin respectively against the parts of said coup ing and having their free ends in proximity.

5. The combination with a hollow shaft made in two sections, of a hollow elastic coupling therefor, a stationary sleeve surrounding the shaft and having a circumferential groove communicating with the interior of said shaft, a fluid pump connected with said groove, a controllable by-pass for the pump, and means for determining the pressure of the fluid supplied to the interior of the shaft.

6. The combination with a shaft made in two sections, of an elastic coupling therefor, consisting of plates having only their outer portions elastic, means for forcing fluid under pressure space bet-ween the rigid port-ions of said plates, and a device for indicating the pressure of the fluid supplied to the space between the plates.

7. The combination with.,a shaft made in two sections, of an elastic coupling therefor, consisting of plates having only their outer portions elastic, means for forcing fluid under pressure Into the space between the prising. members fixedly attached to the adthe axial play thereof,

1nto the space between the plates, a packing confining the fluid to the pllng parts attached to the two sections of 4. The combination with a shaft made in plates, means for measuring the fluid pressure and a packing confining the fluid to the space between the rigid portions of the plates, said packing consisting of a' membrane attached-to one of said plates.

8. The combination with a shaftmade in two sections, of an elastic couplin therefor composed of plates having only t eir outer portions elastic, means for forcing fluid under pressure into the space between the plates, means for measuring the fluid pressure, and a packing consisting of a membrane for confining the fluid to the space between the rigid portions of the plates, one of the plates being composed of two'parts, only one of which is attached to the membrane, while the other part is removable with the shaft section without disturbing said first mentioned part.

9. The combination with a shaft made in sections, of a coupling therefor comprising elastic plates carried by the adjacent ends copies of this arent may be obtained to:

of the sections and inclosing a chamber between them, which plates permit one section to move relatively to the other as the thrust on the shaft varies, means supplyingfluid under pressure to the chamber, a pressure;

indicating device and means securing the rims of the-plates to each other to transmit motion from one section to the other.

10. The combination with a shaft made in sections that are movable relatively to each other, of elastic members on the adjacent ends of the sections that inclose a chamber between them, devices for supplying fluid under pressure to the hamber, a pressure indicatmg device and means for transmitting motion from one member to the other.

In witness whereof, I have hereunto set my hand this 13th day of September, 1910.

, PAUL WAGNER. Witnesses:

ERICK Uenumin, GUSTAV HULBROCK.

five cents each, by addressing the "Commissioner of latentl, Washington, D. c." 

